Some Aspects of the Scattering of Light and Microwaves on Non-Spherical Raindrops

Abstract

A review of the author’s work on the study of the microphysics of rain is carried out. The effect of an anomalously high modulation of light scattered by oscillating drops of water, which consists in the formation of powerful pulses of light when illuminating an oscillating drop with continuous light and observation at scattering angles near a first-order rainbow, is described and explained. The anomalous scattering tracks obtained in the photographs provide information on the mass, average shape, mode, and amplitude of oscillations for each drop, by analogy with the Wilson camera. In field measurements, spatial selection of droplets by size was detected, when droplets of different sizes were grouped in different parts of space. The theoretical substantiation of the grouping of rain particles in space under the influence of wind gusts is carried out. It has been shown that the grouping and clustering of raindrops affects the relationship between radar reflectivity Z and rain intensity R. The influence of non-sphericity and oscillation of raindrops on the scattering of microwave radiation is studied. Polarization methods are proposed for enhancing or sharply reducing the contributions of the asphericity of raindrops to reflected radar signals.